Flexible metallic sheaths for cables



April 18, 1967 M. HEUPGEN 3,

FLEXIBLE METALLIC SHEATHS FOR CABLES Filed Sept. 18, 1963 2 Sheets-Sheet1 Hg] 1 3A B C D 20 I 79 a 7 0L. ,7 .JP

III

I? E? III! E fl HEl/Pfifiy April 18, 1967 M. HEUPGEN FLEXIBLE METALLICSHEATHS FOR CABLES 2 Sheets-Sheet 2 Filed Sept. 18, 1963 ei x l 20 MW V.biz/P 5 y W Patented Apr. 18, 1967 4 Claims. (11. 138-177) Thisinvention relates to electric cables provided with protective, flexible,metallic sheaths.

It is known that when such sheaths have a strictly cylindrical form theyoften present insufficient flexibility to permit winding of the soprotected cables. This cylindrical form, which is normally obtained inmanufacture, must therefore be modified to provide said sheaths with thedesirable flexibility.

For this purpose, it has been proposed to form on these metallic sheathshelicoidal undulations by means of turning tools, but the apparatus usedfor this purpose is complex and in a great number of cases it subjectsthe sheaths to excessive torsions.

The essential objectof the instant invention is therefore to produce, onthe sheaths, deformations with such configuration as to make saidsheaths very flexible and which may be obtained by a simple andeconomical process which would not subject the metal to any abnormalmechanical strain.

This is obtained by providing on the electric cable in accordance Withthe instant invention a flexible metallic sheath the undulations ofwhich are obtained by forming on said sheath indentations, arranged incircles, the indentations of successive circular rows staggered relativeto those of the neighbouring rows.

In order to better understand the new arrangement of the cable-sheathingaccording to the present invention, it will be described hereinafter inmore detail with reference to the appended drawings in which:

FIG. 1 represents the undulated cable-sheath;

FIG. 2 is a straight transversal cross-section of a row of indentationsof said sheath;

FIG. 3 is a transversal section view of the sheath and of portions ofembossing members in working position;

FIG. 4 represents the profile of a Wheel performing the undulation andits assembling system;

FIG. 5 represents a transversal section view of different parts of ahead of an undulating machine with wheels and embossing teeth beingshown disengaged from the sheath.

On FIGS. 1 and 2, 1 represents an insulated cable which can beconstituted in many different ways and for this reason it has beenrepresented as a simple cylinder; this cable is protected by a metallicsheath 2 which represents, with relation to its original tubular form,circular, regularly spaced rows A, B, C, D, etc. of a plurality ofrecesses or indentations, designated by 3, 5, 7 and 9, then by 4, 6, 8and 10 etc.; although the edge contours of these recesses or identationsare rounded, they are represented in FIG. 1 by sharp lines for betterclarity. It is seen that the recesses or indentations of the circularrows A, C etc. are angularly oifsetor staggered half a step in relationto those of the neighbouring rows B, D etc. The indentations disposed inthe indicated manner bring into relief projections on the inside of thesheath corresponding on the external surface thereof to undulations theaxes whereof entwine the sheath and follow the doubly-helical dottedlines of FIG. 1 to impart to the sheath an embossed aspect.

Such a configuration is especially advantageous since on the one handthe cable insulation bears on a rounded surface, thus with no risk ofdeterioration, and on the other, it enables a free longitudinal flow ofan insulating fluid which may be used to fill the cable.

In FIGURES 1 and 2, there is represented a sheath the recesses of whichshow an oblong shape produced by the imprint of a rectilinear toothpositioned transversely of the sheath, but it is evident that thisinvention comprises sheaths having recesses of any other shape, such ashemispherical or the like.

Now, there will be described the machine and the operation of a head ofthe machine capable of producing an undulated sheath having fourperipheral indentations of the kind described above. FIG. 3 illustratesthe principle of such operation. The wheels 12, of which there are eightin number, are fixed to the frame of the machine by means of forkedsupports 13 in which they freely turn and are regularly positionedaround a sheath 2 to be undulated. Their respective median planes passthrough the longitudinal axis of the sheath and define betweenthemselves, in the described case, an angle of 45. Furthermore, theaxles of these wheels are coupled by means of eight bevel gear trains 14which, for a reason which will be explained later, are arranged to beaxially slidable on the axles of said wheels, but maintained geared bymeans of clamps 15. The wheels 12 are equipped with removable dentedrims 16 which are selected according to the dimension and the nature ofthe sheath to be undulated. The mounting and the adjustment of thisequipment is carried out in such a manner that the teeth of adjacentrims 16 are mutually offset angularly.

so that at the level of the sheath 2 each tooth of a rim is facing theclearance between teeth of the neighbouring rims. Furthermore, thenumber of teeth is chosen so that with the desired penetration thesheath 2 will always be in gear with at least one set of the dented rims16.

In accordance with these conditions when one of the wheels 12 isanimated with a rotational movement about its own axis, or when a forceperpendicular to the plane of the figure is exerted on the sheath 2, theteeth of the rims 16 will emboss the metal of this sheath producingequidistant staggered indentations, which results in the formation onsaid sheath of very regular undulations.

It is to be noted that the longitudinal profile of the teeth may berectilinear or curvilinear.

At the beginning and at the end of the operation, or eventually duringthe operation or otherwise in order to regulate the depth of penetrationof the teeth, the wheels 12 must be simultaneously engaged or disengagedfrom the sheath by their simultaneous displacement in their respectiveplanes.

For this purpose the head to be undulated is provided with forkedsupports 13 the bases of which are either hinged in suitable manner orare displaceable in the radial slots of a fixed plate. FIGS. 4 and 5illustrate an example of this latter embodiment.

According to FIG. 4 the base of the forked supports 13 comprises at itsextremity a threaded bolt 17; this bolt is disposed in slots, directedas will be indicated later, in the juxtaposed plates 19 and 20. The saidplates are concentric to both the sheath 2 to be undulated and to thecable 1; the plate 19 is rigidly fixed to the frame of the machine whilethe plate 20 can be angularly displaced relative to the plate 19. Bymeans of nuts 21 it is possible to lock plate 20 and thus the forkedsupport 13 to the plate .19.

The slots 19a and 20a in the respective plates 19 and 20 are show-n inthe sector 0 of FIG. 5, which represents a partial sectional view of theundulating head on the plane OP of FIG. 4. It is also shown at 19a thatthe slots in the plate 19 are radial while the slots 20a of plate 20 arein spiral form. When the nuts 21 are loosened, the bolts 17 of theforked supports 13 can be guided simultaneously towards the center 0' orin the opposite direction depending on whether the plate 20 is rotatedin one direction or the other by means of handle 22.

FIG. 5 represents,.in sector M, a partial sectional view of FIG. 4 inthe plan MN; the position of wheels 12, rims 16 and bevel pinions 14When the plate 20 is in the position illustrated in sector 0 withrelation to plate 19; so that the teeth are disengaged from the sheath.It will be noted in comparing this view of sector M with FIG. 3 thatclamp 15 will permit pinions 14 to slide axially on their shafts Whileremaining keyed for mutual rotation.

It will be understood that the described process and apparatus can bemodified in different ways and be applied to the manufacture of flexiblehollow tubes such as are used to sheath flowing fluids, as well as tomanufacture of sheaths which contain electric cables, the latter withtheir sheaths presenting the features of a new industrial product.

I claim:

1. Flexible tubular metallic cable-sheathing comprising; a series ofrecesses or indentations on the external surface of the sheathingarranged circumferentially in rows about said sheathing, individualrecesses or indentations of each said row being staggered with respectto the individual recesses or indentations of the rows immediatelyadjacent thereto, said staggering of alternate rows thereby definingundulations between said recesses or indentations, whereby saidundulations entwine a cable in doubly-helical fashion to enhance theflexibility of said tubular sheathing over that displayed in anon-indented condition.

2. A flexible tubular metallic cable-sheathing as claimed in claim 1, inwhich the shape of said recesses or indentations is that which isproduced by the imprint of a rectilinear tooth located in a transversalposition with respect to the sheath.

3. A flexible tubular metallic cable-sheathing as claimed in claim 1, inwhich the shape of said recess is that which is produced by the imprintof a curvilinear tooth located in a transversal position with respect tothe sheath.

4. A flexible tubular metallic cable-sheathing as claimed in claim 1, inwhich the shape of said recess is that which is produced by the imprintof a substantially spherical tooth located in a 'transversal positionwith respect to the sheath.

References Cited by the Examiner UNITED STATES PATENTS 176,911 5/1876Whysall- 72-194 344,847 7/1886 Mersereau 138-177 1,685,518 9/1928Burrows 72194 1,962,876 6/1934 Reinert et al l38l77 2,259,433 10/1941Kitto 13838 2,265,226 12/1941 Clewell (it al 138177 2,361,318 10/1944Orr et al. 138-177 2,649,194 5/1953 Hytte 13838 SAMUEL ROTHBE'RG,Primary Exmnirzer.

LAVERNE D. GEIGER, Exan'tiner.

H. ARTIS, Assistant Examiner.

1. FLEXIBLE TUBULAR METALLIC CABLE-SHEATING COMPRISING; A SERIES OFRECESSES OR INDENTATIONS ON THE EXTERNAL SURFACE OF THE SHEATHINGARRANGED CIRCUMFERENTAILLY IN ROWS ABOUT SAID SHEATHING, INDIVIDUALRECESSES OR INDENTATIONS OF EACH SAID ROW BEING STAGGERED WITH RESPECTTO THE INDIVIDUAL RECESSES OR IDENTATIONS OF THE ROWS IMMEDIATELYADJACENT THERETO, SAID STAGGERING OF ALTERNATE ROWS THEREBY DEFININGUNDULATIONS BETWEEN SAID RECESSES OR INDENTATIONS, WHEREBY SAIDUNDULATIONS ENTWINE A CABLE IN DOUBLY-HELICAL FASHION TO ENHANCE THEFLEXIBILITY OF SAID TUBULAR SHEATHING OVER THAT DISPLAYED IN ANON-INDENTED CONDITION.